Trees are useful to man in three very important ways: they provide him with wood and other products, they give him shade, and they help to prevent drought and floods.

　　Unfortunately, in many parts of the world man has not realized that the third of these services is the most important. In his eagerness to draw quick profit from the trees, he has cut them down in large numbers, only to find that without them he has lost the best friends he had.

　　Two thousand years ago a rich and powerful country cut down its trees to build warships, with which to gain itself an empire. It gained the empire but, without its trees, its soil became hard and poor. When the empire fell to pieces, the country found itself faced by floods and starvation.

　　Even though a government realizes the importance of a plentiful supply of trees, it is difficult for it to persuade the villager to see this. The villager wants wood to cook his food with, and he can earn money by making charcoal or selling wood to the townsman. He is usually too lazy or too careless to plant and look after trees. So unless the government has a good system of control, or can educate the people, the forests will slowly disappear.

　　This does not only mean that the villagers? sons and grandsons have fewer trees. The results are even more serious. For where there are trees their roots break the soil up—allowing the rain to sink in and also hold the soil, thus preventing it being washed away easily, but where there are no trees, the soil becomes hard and poor. The rain falls on hard ground and flows away on the surface, causing floods and carrying away with it the rich topsoil, in which crops grow so well. When all the topsoil is gone, nothing remains but a worthless desert.

63. The purpose that the writer wrote this article for is ____ .

　A. to tell people that trees are very useful to man

　B. to warn people not to cut down trees any more

　C. to warn that man mustn't destroy forests any more

　D. to explain how trees help to prevent drought and floods

64. In the writer's opinion, ____ , or the forests slowly disappear.

　A. measure must be taken                      B. people shouldn't draw benefit from the tree

　C. government must realize the serious results      D. unless trees never be cut down

65. According to the article we know it is ____ to prevent the forests from slowly disappearing.

　A. necessary but impossible                    B. necessary but difficult

　C. impossible and unimportant                  D. difficult and impossible

66. In the last two paragraphs the writer wanted to make it clear that ____ .

　A. where there are no trees, the soil becomes hard and poor

　B. where there are many trees, there are fewer floods

　C. where there are no trees, the land might become desert slowly

　D. floods will make the land become desert

完形填空

阅读下面短文，从短文后所给各题的四个选项中选出能填入相应空白处的最佳选项。

　　Our plan was to drive into Cambridge, catch the 7:34 train to Liverpool Street Station, then to separate and meet again for lunch. Although we arrived at Liverpool Street Station at 10:30, Joan 1 that she would go to see the Crown Jewels in the Tower of London 2 we went shopping. It was only after her sister had 3 into the fog that my wife realized that we hadn't decided where we should 4 her for lunch. 5 I had our three tickets for the concert in my pocket, this was indeed a 6 . There seemed to be nothing we could do but take a taxi to the Tower of London. However, we didn't find her.

　　It was now one o'clock, and the concert would begin at 2:30.“Perhaps she'll 7 waiting outside the concert hall,”said my wife hopefully. By this time the fog was so thick that the road traffic had to 8 , and the only way to get there was 9 underground railway. Hand in hand we 10 our way along the road to where we thought the 11 station should be. An hour later we found Tower Hill Station.

　　By now it was far 12 late even to try to get to the concert hall before the performance began at 2:30. So we decided to 13 to Cambridge. It took seven long hours instead of two as usual to 14 that journey. 15 were we able to get any food and drink on the train. Tired and hungry we finally reached home at ten. 16 the door, we heard the sound of the telephone bell. It was Joan; she had seen the Crown Jewels, had managed to get another ticket for the concert, and had had a wonderful 17 at a restaurant near the hotel where she had decided to stay at night. Now she was 18 us to discover 19 we had had an equally 20 day.

1．

[　　]

A．hoped　　　　　　B．decided

C．suggested　　　　　D．wanted

2．

[　　]

A．during　　　　　B．when

C．since　　　　　　D．before

3．

[　　]

A．hidden　　　　　　B．run

C．disappeared　　　　D．entered

4．

[　　]

A．see　　　　　　B．meet

C．wait　　　　　　D．call

5．

[　　]

A．Though　　　　　B．When

C．Since　　　　　　D．For

6．

[　　]

A．chance　　　　　　B．subject

C．matter　　　　　　D．problem

7．

[　　]

A．mind　　　　　　B．forget

C．insist on　　　　　D．think of

8．

[　　]

A．finish　　　　　　B．begin

C．stop　　　　　　D．start

9．

[　　]

A．with　　　　　　B．on

C．by　　　　　　D．through

10．

[　　]

A．made　　　　　　B．pushed

C．found　　　　　　D．felt

11．

[　　]

A．nearby　　　　　　B．near

C．nearer　　　　　　D．nearest

12．

[　　]

A．too　　　　　　B．very

C．quite　　　　　　D．so

13．

[　　]

A．walk　　　　　　B．drive

C．ride　　　　　　D．return

14．

[　　]

A．do　　　　　　B．make

C．get　　　　　　D．have

15．

[　　]

A．So　　　　　　B．Hardly

C．Nor　　　　　　D．Thus

16．

[　　]

A．Opening　　　　　　B．Knocking at

C．Closing　　　　　　D．Going to

17．

[　　]

A．breakfast　　　　　　B．lunch

C．afternoon tea　　　　　D．dinner

18．

[　　]

A．asking　　　　　　B．thinking

C．ringing　　　　　　D．wanting

19．

[　　]

A．why　　　　　　B．how

C．where　　　　　　D．whether

20．

[　　]

A．busy　　　　　　B．successful

C．free　　　　　　D．sad

完形填空：阅读下面短文，掌握其大意，然后从各题所给的四个选项中选出一个最佳答案。（共20小题，每小题1.5分）
In the past, man did not have to think about the protection of his environment. There were few people on the earth, and natural resources seemed to be　46　.                    Today things are　 47　 , the world has become too　 48　 . We are using up our natural resources too quickly, and at the same time we are　 49　 our environment with dangerous chemicals. If we continue to do this, human life on the earth　 50　 survive.
　　Everyone　51　 today that if too many fish are taken from the sea, there will soon be none left. Yet, with modern fishing　 52 , more and more fish are caught. We know that if too many trees are cut down, 　53　 will disappear and nothing will grow on the land. Yet, we　 54　 to use bigger and more powerful machines to　55　 more and more trees.
　　We realize that if rivers are polluted with waste products from factories, we will die.　 56　 , in most countries wastes are　 57　put into rivers or into the sea, and there are　 58　 laws to stop this. We know, too, that if the　 59　of the world continues to rise at the present rate, in a few years there will not be enough 60　. What can we do to solve these problems ?
　  If  we eat more vegetables and less　 61　 , there will be more food available for everyone. Land that is used to grow crops　 62　 five times more people than land where animals are kept. Our natural resources will　 63　 longer if we learn to recycle them. The world population will not rise so quickly if people use modern methods of birth 64　 .
　　Finally, if we educate people to think about the problems, we shall have a better and clearer 65　in the future.

D
　　In the atmosphere,carbon dioxide actd rather like a one-way mirror or the glass in the roof of a greenhouse which allows the sun's rays to enter but prevents the heat from excaping.
　　According to a weather expert's prediction,the atmosphere will be 3 warmer in the year 2050 than it is today, if man continues to burn luels at the present rate. If this warming up took place,the ice caps in the poles would begin to melt,thus raising sea level several meters and severely flooding coastal cities.Also，the increase in atmospheric temperature would lead to great changes in the climate of the northern hemisphere(半球),psooicbly resulting in an alteration of earth's chief food growing zones.
　　In the past,concern about a man - made warming of the earth has concentrated on the Arctic because the Antarctic is much colder and has a much thicker ice sheet.But the weather experts are now paying more attention to West Antarctic,which may be affected by a warming on the scale that will possibly take place in the next fifty years from on burning of fuels.
　　Satellite pictures showthat large areas of Antarctic ice are already disappearing.The evidence available suggests that a warming has taken place.This fits the theory that carbon dioxide warms the earth.
　　However,most of the fuel is burnt in the northern hemisphere,where temperatures seem to be falling.Scientists conclude,therefore,that up to now natural influences on the weather have exceeded those caused by man.The question is:Which natural cause has most effect on the weather?
　　One possibility is the variable behavior of the sun.Astronomers at one research station have studied the hot spots and cold spots(that is,the relatively less hot spots) on the sun. As the sun rotates(旋转),every 27.5 days,it presents hotter or colder faces to the earth,and different aspects to different parts of the earth.This seems to have a considerable effect on the distribution of the earth's atmospheric pressure,and consequently on wind circulation.The sun is also variable over a long term:its heat output goes up and down in cycles,the latest trend being downward.
　　Scientists are now finding mutual relations between models of solar weather interactions and the actual climate over many thousands of years ,including the last Ice Age.The problem is that the models are predicting that the world should be entering a new Ice Age and it is not.
　　One way of solving this theoretical difficulty is to assume a delay of thousands of years while the solar effects overcome the inertia(不活动，惰性) of the earth's climate.If this is right,the warming effect of carbon dioxide might thus be serving as a useful counter balance to the sun's diminishing heat.
　　68.It can be concluded that a concentration of carbon dioxide in the atmosphere would ___.
　　　A.mean a warming - up im the Arctic
　　　B.raise the temperature of the earth's surface
　　　C.prevent the sun's rays from reaching the earth's surface
　　　D.account for great changes in the climate in the northern hemiphere
　　69.Although the fuel consumption is greater in the northern hemisphere,temperatures there seem to be falling.This is _______.
　　　A.mainly because the levels of carbon dioxide are rising
　　　B.partly due to variations in the output of solar energy
　　　C.possibly because the ice caps in the poles are melting
　　　D.exclusively due to the effect of the inertia of the earth's climate
　　70.On the basis of their models,scientists are of the opinion that ________.
　　　A.the climate of the world should be becoming cooler
　　　B.the new Ice Age will be delayed by the greenhouse effect
　　　C.the man - made warming effect helps to increase the solar effects
　　　D.it will take thousands of years for the inertia of the earth's climate to take effect

完形填空：阅读下面短文，掌握其大意，然后从各题所给的四个选项中选出一个最佳答案。（共20小题，每小题1.5分）

   In the past, man did not have to think about the protection of his environment. There were few people on the earth, and natural resources seemed to be　46　 .                    Today things are　 47　 , the world has become too　 48　 . We are using up our natural resources too quickly, and at the same time we are　 49　 our environment with dangerous chemicals. If we continue to do this, human life on the earth　 50　 survive.

　　Everyone　51　 today that if too many fish are taken from the sea, there will soon be none left. Yet, with modern fishing　 52 , more and more fish are caught. We know that if too many trees are cut down, 　53　 will disappear and nothing will grow on the land. Yet, we　 54　 to use bigger and more powerful machines to　 55　 more and more trees.

　　We realize that if rivers are polluted with waste products from factories, we will die.　 56　 , in most countries wastes are　 57　 put into rivers or into the sea, and there are　 58　 laws to stop this. We know, too, that if the　 59　 of the world continues to rise at the present rate, in a few years there will not be enough 60　. What can we do to solve these problems ?

　  If  we eat more vegetables and less　 61　 , there will be more food available for everyone. Land that is used to grow crops　 62　 five times more people than land where animals are kept. Our natural resources will　 63　 longer if we learn to recycle them. The world population will not rise so quickly if people use modern methods of birth 64　 .

　　Finally, if we educate people to think about the problems, we shall have a better and clearer 65　 in the future.

1.A. beautiful            B. unlimited               C. rare                        D. valuable

2.A. common            B. the same               C. changeable     D. different

3.A. crowded            B. small                      C. dirty                        D. busy

4.A. protecting         B. saving               C. polluting                D. fighting

5.A. may not             B. will not                   C. shall not                D. could not

6.A. wonders            B. realizes                  C. consider                D. discovers

7.A. poles                   B. boats                      C. methods                D. ideas

8.A  mountains      B. the sea                      C. trees                      D. forests

9.A. continue            B. have                       C. ought                     D. go on

10.A. grow                 B. plant                       C. save                        D. cut down

11.A. Thus       B. However    

C. Generally speaking  D. Therefore

12.A. still                    B. even                       C. also                         D. certainly

13.A. too many         B. a few                      C. some                      D. few

14.A. production      B. pollution                C. population       D. revolution

15.A. houses             B. vegetables      C. food                        D. lives

16.A. fruit                  B. meat                      C. fish                          D. grain

17.A. feeds                B. increases              C. supplies                 D. helps

18.A. use                    B. stay                        C. keep                       D. last

19.A. control             B. born                        C. plan                        D. reward

20.A. nature              B. sea                    C. planet               D. forest